The present invention relates to a method for operating a protective device for elements in a vehicle.
Bites to cars by martens became an issue in the 80s. The annual damage to motor vehicles by martens is estimated at several hundreds of thousands of cases. In the year 2011 alone there were over 229,000 insurance cases noted by the professional body of the German insurance business. However, the true figures are significantly larger since the insurance statistics only cover damage which clients have made public. Particularly the beech marten has become accustomed to the living habits of people and is increasingly living in their proximity as a species which can adapt to humans. In this context it has been found that, as has been long assumed, stone martens do not form nests in cars because they are attracted to the smell of hot rubber or to the composition of the plastics but rather simply because of their behavior. The engine cavity provides the beech martens with an attractive refuge with versatile possibilities. In this context, vehicles which commute between different locations and are parked in the open over night are particularly at risk. Once different martens at the two locations have marked their respective territory in the vehicle, the animals attempt to defend this territory, resulting in biting attacks. For a vehicle owner, damage by martens can become an expensive and also dangerous matter. Insulating materials in the engine compartment are the least of the car owner's problems here. Cables and hoses of all types (axle boots, spark plug cables, cooling water pipes, brake lines, pipes of the windscreen wiper system, lambda probe cables, etc.) are at particular risk and are preferred objects for biting. In this context, the bite points are sometimes difficult to discover, since the sharp teeth of the animals leave indents which are approximately only the size of a knitting needle.
Possible consequences are, for example, immobilization (as a result of defective ignition cable), a vehicle fire (as a result of insulating material which has caught fire) or an accident (as a result of a defective brake line). It is thus appropriate to take defensive measures throughout the year.
It is known to use a sheath to protect elements in motor vehicles, in particular lines such as, for example, ignition lines, which are freely accessible and are at risk from bites by wild animals, specifically bites by martens. Since the lines generally run in a curved fashion owing to the restricted spatial conditions in a motor vehicle, the sheath is formed by juxtaposition of what are referred to as individual beads. These individual beads are short tubular sections whose walls are embodied in a stepped fashion such that they can be mounted in a partially overlapping fashion and laid in a curved fashion. A disadvantage with this sheath is that it is costly, since it is composed of beads which have to be manufactured individually and which have to be counted as they are applied to the lines to be protected, with the result that in addition to high manufacturing costs the sheath is also burdened with high mounting costs as a result of the type of mounting.
Further defensive measures would be wire mesh under the engine compartment or large repellent objects under the vehicle. However, these often have a chronologically limited effect. Martens are very careful animals and usually do not behave in a risky way, but although they avoid unaccustomed fixtures for a certain time, they do not do so for ever.
High-voltage devices are also known for repelling martens. Contact panels which are mounted in the engine compartment and are charged by a high-voltage generator give the marten an electric shock on contact, in accordance with the electric fence principle. The positive effect here is that it keeps away martens over the long term without injuring them (source: Wikipedia/Marderabwehr [Protection against martens]). However, an electric current requires a circuit to be closed. A ground (negative pole) is necessary for this, for example via the bodywork of the vehicle or other blank metal motor parts. Water hoses are also composed of conductive material. It is disadvantageous therefore that the required negative pole is transported via the vehicle. In addition, it is disadvantageous that in newer vehicles there are fewer conductive surfaces available, since construction in the engine compartment features a large amount of plastic, surface coating agents and sound insulation.
There is therefore a need for a more effective and more cost-effective protective device in a vehicle.